Although the Wankel engine has long been a source of mystery to many, particularly to the people who make rules for sports-car racing, more is better in rotary hummers just as it is in conventional engines. More as in more displacement and more air-fuel mixture crammed into the combustion chamber.

Mazda RX-7 specialist Peter Farrell grasps both halves of that power formula. Since you can't bore or stroke a rotary engine, Farrell increases the displacement of the 1308cc two-rotor 13B Mazda engine by replacing it with a 1950cc 20B three-rotor engine from a Mazda Cosmo, a hot coupe that was never exported to the U.S.

To accommodate the bigger, heavier (by 130 pounds) engine, Farrell had to relocate the transmission about five inches rearward, shorten the driveshaft, and fabricate a custom front subframe — all to avoid relocating the steering rack. "It makes the car pretty squirrelly if you move the rack," he says.

To cram more air-fuel mixture into this larger rotary, Farrell discarded the 13B's stock sequential twin turbos in favor of a single turbo with a bigger turbine housing and variable boost. He adapted 13B rotor housings, to take advantage of their larger ports, and swapped the stock ECU for a fully programmable Electromotive TEC 1 system. So equipped, he can vary boost from about 15 psi for pump gas to as much as 25 psi with "exotic race gas." Burning premium unleaded, Farrell says the three-rotor spins up 600 horsepower at the flywheel, and the output soars to more than 700 horsepower on racing fuel.

Torque is always lower on rotaries, but this one makes 450 pound-feet of it across a very broad band, making it possible to motor around town in fourth gear, as though the car had a continuously variable automatic.

Speaking of transmissions, Farrell retained the stock five-speed manual and stock rear end of the RX-7. The clutch, however, is a narrow-engagement racing unit, which made for lurchy launches.

Owned by Phil Hamlin, a Colorado Internet entrepreneur, the RX-7 seen here represents a $47,000 investment in addition to the cost of the car, according to Farrell. On our road drive, it drew positive comments for its massive thrust and decent ride comfort, but it also suffered a number of problems. When it arrived, the engine had a massive flat spot due to a calibration problem with its engine-control computer. Then one of the pressure-relief valves blew off the intake manifold. Finally, a broken T-fitting in the turbo plumbing, caused by the engine's rotating slightly at full throttle, allowed the boost to skyrocket and potentially grenade the engine. The repair sidelined the car for about two hours.

Although the PFS RX-7 couldn't quite reach 150 mph on our test course, it finished in a solid second place by easily hitting 140 and running an overall time of 5.9 seconds quicker than the Mallett Corvette. The RX-7 also turned in the best road-course time — three seconds quicker than the Mallett's and undoubtedly facilitated by Peter Farrell's extensive road-racing experience. However, in its final run, a radiator hose ruptured in spectacular fashion, and the RX-7 went onto the trailer.

Nevertheless, Farrell once again demonstrated that this superb sports car could be formidable in the right hands, although even he admits that it may be time to move on.